Osseointegration final

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2. The Amphora Peter Apelgren 3. ContentsIntroductionHistorical reviewDefinitionBone density classificationBiological considerations forosseointegration Bone implant interface Bone remodeling Foreign body reaction 4. Bone to implant interface Mechanism of osseointegration Ultrastructure in osseointegration Destruction of osseointegration Soft tissue implant interface Peri-implant membrane Disease activity in peri-implant tissue Neuromuscular system as it relates to the implant 5. . Factors influencing osseointegration Osseointegration vs biointegration Success criteria for osseointegrated implants Clinical applications of osseointegration Future of osseointegration Summary & Conclusion References 6. IntroductionThe ideal goal of modern dentistry is to restore thepatient to normal contour, function..Implant dentistry is unique because of its ability toachieve this goal regardless of the stomatognathicsystem. 7. ..The primary function of an implant is to act as anabutment for prosthetic device.The present surge in the use of implants wasinitiated by Branemark (1952)..Described the relationship between titanium andbone for which they coined the termosseointegration. 8. DefinitionThe word osseointegration consists of OSthe Latin word for bone and integrationderived from Latin word meaning the state ofbeing combined into a complete whole.Osseointegration is defined as a direct boneanchorage to an implant body which canprovide a foundation to support a prosthesis. Direct structural and functional connection betweenordered, living bone and surface of a load carrying implant . 9. .. American Academy of Implant Dentistry defined it as contact established without interposition of non bone tissue between normal remodeled bone and on implant entailing a sustained transfer and distribution of load from the implant to and within bone tissue. 10. Historical Review The concept of osseointegration was developed and the term wascoined by Dr. Per-Ingvar Branemark, Professor at the institute for Applied Biotechnology, University ofGoteborg, Sweden. 11. Initial concept of osseointegration stemmedfrom vital microscopic studies ofmicrocirculation in bone repair mechanisms.Titanium chamber was surgically insertedinto the tibia of of a rabbit.It was considered the best material forartificial tooth root replacement. 12. .. Many studies followed involving titanium implants being placed into jaws of dogs. Direct bone anchorage has been shown to be very strong. A force of over 100kg was applied to dislodge an implant. Based on such a consequence the foundation for Osseo integration and the Branemark implant system was established in 1952. 13. Studies on humans wereconducted by means of animplant optical titanium chamberin a twin pedicle skin tube on theinside of the left upper arm ofvolunteers.Tissue reactions were studied inlong term experiments.All this lead to the treatment offirst edentulous patient in 1965. 14. History of Branemark system categorized inthree stages Early stage (1965-1968) Developmental stage (1968-1971) Production stage (1971 present) 15. Bone density classification (Misch) 16. Biological Considerations forOsseointegrationBone implant interface When compared to compact bonespongy bone has less density andhardness is not a stable base forprimary fixture fixation. In the mandible the spongy boneis more dense than maxilla. With primary fixation incompact bone, osseointegrationin the maxilla require a longerhealing period. 17. Bone remodelingOsseointegration requires new bone formationaround the fixture. A process resulting fromremodeling within bone tissue.Osteoblastic and osteoclastic activity helpsmaintain blood calcium without change inquantity of bone. 18. .. To maintain a constant level of bone remodeling there should be proper local stimulation, crucial levels of thyroid hormone, calcitonin and vitamin D. Occlusion or occlusal force stimulus are both important to optimal bone remodeling. 19. Foreign body reaction Organization or an antigen antibody reaction occurs when a foreign body is present in the body. This reaction occurs in the presence of a protein but with implant materials devoid of proteins no antigen antibody reaction. 20. .. When titanium is used no foreign body reaction are seen. The implant material is an important factor for Osseo integration to occur. 21. Bone to implant interfaceTwo basic theories Fibro-osseous integration by Linkow, James & Weis Osseointegration by Branemark Meffert divided osseointegration Adaptive osseointegrationBiointegration 22. American Academy of implant dentistry definedfibrous integration as tissue to implant contact withhealthy dense collagenous tissue between theimplant and bone. 23. .. The fibers are arranged irregularly, parallel to the implant body, when forces are applied they are not transmitted through the fibers. So no bone remodeling expected in fibro- integration. 24. Ichida & Caputo (1986) used photo-elastic analysis tostudy the stress concentration along the implantthreads and sharp edges when a connective tissue likestructure was included in the analysis.Even stress distribution was seen when there wasdirect contact with a bone like structure.They concluded that implants with fibro-osseousintegration had a tendency of increased mobility. 25. A direct bone implant interface occurs when animplant is allowed to heal in bone undisturbed.Main factors affecting osseointegration include Implant oxide layer contamination. Poor temperature control during drilling. 26. A minimum of 3 month healing in mandible and 6months in maxilla is necessary before load isapplied.If osseointegration does not occur or a fibrousconnective tissue forms around the implantorganization process continues. 27. Biological process of implant osseointegrationThe healing process of implantsystem is similar to primarybone healing.Titanium dental implants showthree stages of healing. 28. .. OSTEOPHYLLIC STAGE When a implant is placed into the cancellous marrow space blood is initially present between implant and bone. Only a small amount of bone is in contact with the implant surface; the rest is exposed to extracellular fluids. Generalized inflammatory response to the surgical insult. 29. .. By the end of first week, inflammatory cells areresponding to foreign antigens. Vascular ingrowth from the surrounding vital tissuesbegins by third day. A mature vascular network forms by 3 weeks. Ossification also begins during the first week and theinitial response observed in the migration of osteoblastsfrom the trabacular bone which can be due to therelease of BMPs. The osteophyllic phase lasts about 1 month. 30. OSTEOCONDUCTIVE PHASEOnce they reach the implant, the bone cells spreadalong the metal surface laying down osteoid.Initially this is an immature connective tissuematrix and bone deposited is a thin layer of wovenbone called foot plate. 31. .. Fibro-cartilaginous callus is eventuallyremodeled into bone callus. This process occurs during the next 3 months Four months after implant placement the maximum surface area is covered by bone. 32. OSTEOADAPTIVE PHASE The final phase begins approximately 4 months afterimplant placement. Once loaded implants do not gain or loose bone contact butthe foot plates thicken in response and some reorientation ofthe vascular pattern may be seen. 33. .. Grafted bone integrates to a higher degree than the natural host bone to the implant. To achieve optimal results an osseointegration period of 4 months is recommended for implants in graft bone and 4 to 8 months for implant placed in normal bone. 34. Ultrastructure in osseointegration Osseointegrated fixturesunder occlusal loads aresurrounded by cortical andspongy bone. The cortical bone to fixturesurface interface hascanaliculi participating inelectrolyte transportationnear oxide layer. 35. .Osseointegration in spongy bone occurs asbone trabaculae approaches the fixture andcome into intimate contact with oxide layer.Ground substance forms and fills spacesbetween bone trabeculae this fuses withoxide layer. 36. Destruction of OsseointegrationThe main contributing factor to bone resorption arelocal inflammation from plaque and trauma fromocclusion Direct action of plaque products induces formation ofosteoclasts. Plaque products at directly on bone destroying itthrough a non cellular mechanism. Stimulate gingival cells, which release mediators forosteoclast formation. 37. Plaque causes gingival cells to release agents which act ascofactors in bone resorption and which destroy bone bydirect chemical action without osteoclasts.Bone resorption can be caused by prematureloading.12 months following fixture insertion verticalbone loss is observed due to traumaticsurgical procedure. Vertical bone loss approximately 1 to 1.5 mm in first year Marginal bone loss is 0.05 to 0.1 mm in first year These measurements can be used a reference and in abone loss condition should be evaluated to minimizefailure. 38. Peri-implant membrane With the osseointegrated implantthe abutment to fixture junctioncorresponds to cementoenameljunction present in naturaldentition. Peri-implant membrane is similarto that present in naturaldentition, consisting of peri-implant free gingiva. 39. .The sulcular epithelium forms the peri-implant gingival crevice and junctionalepithelium attaches to the abutment forminga cuff.With a tight cuff and filamentous attachmenta membrane is sealed tightly andfunctionally to the abutment surface. 40. Disease activity in peri-implant tissueThe fibrous connective tissue capsuleformed around an implant generally has lowdifferentiating capabilities such that it alsohas less resistance against bacterial bi-products and does not respond well toocclusal stimulation.An osseointegrated implant has periosteumdirectly covering the neck of the fixture.Which may act as a barrier against